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+---
+title: String.fromCodePoint()
+slug: Web/JavaScript/Reference/Global_Objects/String/fromCodePoint
+translation_of: Web/JavaScript/Reference/Global_Objects/String/fromCodePoint
+---
+<div>{{JSRef}}</div>
+
+<p><strong><code>String.fromCodePoint()</code> 静态方法返回使用指定的代码点序列创建的字符串。</strong></p>
+
+<div>{{EmbedInteractiveExample("pages/js/string-fromcodepoint.html")}}</div>
+
+
+
+<h2 id="语法">语法</h2>
+
+<pre class="syntaxbox"><code>String.fromCodePoint(<var>num1</var>[, ...[, <var>numN</var>]])</code></pre>
+
+<h3 id="参数">参数</h3>
+
+<dl>
+ <dt><code>num1, ..., num<em>N</em></code></dt>
+ <dd>一串 Unicode 编码位置,即“代码点”。</dd>
+ <dt>
+ <h3 id="返回值">返回值</h3>
+
+ <p>使用指定的 Unicode 编码位置创建的字符串。</p>
+ </dt>
+</dl>
+
+<h3 id="异常">异常</h3>
+
+<dl>
+ <dt>{{jsxref("RangeError")}}</dt>
+ <dd>如果传入无效的 Unicode 编码,将会抛出一个{{jsxref("RangeError")}} (例如: "RangeError: NaN is not a valid code point")。</dd>
+</dl>
+
+<h2 id="说明">说明</h2>
+
+<p>该方法返回一个字符串,而不是一个 {{jsxref("String")}} 对象。</p>
+
+<p>因为 <code>fromCodePoint()</code> 是 {{jsxref("String")}} 的一个静态方法,所以只能通过 <code>String.fromCodePoint()</code> 这样的方式来使用,不能在你创建的 {{jsxref("String")}} 对象实例上直接调用。</p>
+
+<h2 id="例子">例子</h2>
+
+<h3 id="使用_fromCodePoint()">使用 <code>fromCodePoint()</code></h3>
+
+<pre class="brush: js">String.fromCodePoint(42); // "*"
+String.fromCodePoint(65, 90); // "AZ"
+String.fromCodePoint(0x404); // "\u0404"
+String.fromCodePoint(0x2F804); // "\uD87E\uDC04"
+String.fromCodePoint(194564); // "\uD87E\uDC04"
+String.fromCodePoint(0x1D306, 0x61, 0x1D307) // "\uD834\uDF06a\uD834\uDF07"
+
+String.fromCodePoint('_'); // RangeError
+String.fromCodePoint(Infinity); // RangeError
+String.fromCodePoint(-1); // RangeError
+String.fromCodePoint(3.14); // RangeError
+String.fromCodePoint(3e-2); // RangeError
+String.fromCodePoint(NaN); // RangeError
+</pre>
+
+<pre class="brush: js">// String.fromCharCode() 方法不能单独获取在高代码点位上的字符
+// 另一方面,下列的示例中,可以返回 4 字节,也可以返回 2 字节的字符
+// (也就是说,它可以返回单独的字符,使用长度 2 代替 1!)
+console.log(String.fromCodePoint(0x2F804)); // or 194564 in decimal
+</pre>
+
+<h2 id="Polyfill">Polyfill</h2>
+
+<p><code>String.fromCodePoint</code> 方法是 ECMAScript2015(ES6)新增加的特性,所以一些老的浏览器可能还不支持。可以通过使用下面的 polyfill 代码来保证浏览器的支持:</p>
+
+<pre class="brush: js">if (!String.fromCodePoint) (function(stringFromCharCode) {
+    var fromCodePoint = function(_) {
+      var codeUnits = [], codeLen = 0, result = "";
+      for (var index=0, len = arguments.length; index !== len; ++index) {
+        var codePoint = +arguments[index];
+  // correctly handles all cases including `NaN`, `-Infinity`, `+Infinity`
+  // The surrounding `!(...)` is required to correctly handle `NaN` cases
+  // The (codePoint&gt;&gt;&gt;0) === codePoint clause handles decimals and negatives
+        if (!(codePoint &lt; 0x10FFFF &amp;&amp; (codePoint&gt;&gt;&gt;0) === codePoint))
+          throw RangeError("Invalid code point: " + codePoint);
+        if (codePoint &lt;= 0xFFFF) { // BMP code point
+          codeLen = codeUnits.push(codePoint);
+        } else { // Astral code point; split in surrogate halves
+          // https://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
+          codePoint -= 0x10000;
+          codeLen = codeUnits.push(
+  (codePoint &gt;&gt; 10) + 0xD800, // highSurrogate
+  (codePoint % 0x400) + 0xDC00 // lowSurrogate
+  );
+        }
+        if (codeLen &gt;= 0x3fff) {
+          result += stringFromCharCode.apply(null, codeUnits);
+          codeUnits.length = 0;
+        }
+      }
+      return result + stringFromCharCode.apply(null, codeUnits);
+    };
+    try { // IE 8 only supports `Object.defineProperty` on DOM elements
+      Object.defineProperty(String, "fromCodePoint", {
+        "value": fromCodePoint, "configurable": true, "writable": true
+      });
+    } catch(e) {
+      String.fromCodePoint = fromCodePoint;
+    }
+}(String.fromCharCode));
+</pre>
+
+<h2 id="规范">规范</h2>
+
+<table class="standard-table">
+ <tbody>
+ <tr>
+ <th scope="col">规范</th>
+ <th scope="col">状态</th>
+ <th scope="col">备注</th>
+ </tr>
+ <tr>
+ <td>{{SpecName('ES2015', '#sec-string.fromcodepoint', 'String.fromCodePoint')}}</td>
+ <td>{{Spec2('ES2015')}}</td>
+ <td>Initial definition.</td>
+ </tr>
+ <tr>
+ <td>{{SpecName('ESDraft', '#sec-string.fromcodepoint', 'String.fromCodePoint')}}</td>
+ <td>{{Spec2('ESDraft')}}</td>
+ <td> </td>
+ </tr>
+ </tbody>
+</table>
+
+<h2 id="浏览器兼容性">浏览器兼容性</h2>
+
+<p class="hidden">The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out <a href="https://github.com/mdn/browser-compat-data">https://github.com/mdn/browser-compat-data</a> and send us a pull request.</p>
+
+<p>{{Compat("javascript.builtins.String.fromCodePoint")}}</p>
+
+<h2 id="参见">参见</h2>
+
+<ul>
+ <li>{{jsxref("String.fromCharCode()")}}</li>
+ <li>{{jsxref("String.prototype.charAt()")}}</li>
+ <li>{{jsxref("String.prototype.codePointAt()")}}</li>
+ <li>{{jsxref("String.prototype.charCodeAt()")}}</li>
+</ul>